TISSUE DISTRIBUTION OF CEFMINOX IN BEAGLE DOGS

A new cephamycin antibiotic, cefminox (MT-141, CMNX), was intravenously infused into Beagle dogs at a dose of 40 mg/kg in order to study it's distribution to various tissues. The following results were obtained. 1. The maximum serum concentration of CMNX observed at the end of the infusion period was 102.3 μg/ml, and then the concentration decreased. The biological half-life of CMNX in serum was 37.0 minutes. This half-life was similar to the results of previous studies with Beagle dogs and rabbits. 2. The maximum concentrations in tissues and body fluids were highest in B-bile followed by kidney, urinary bladder, serum, liver, vagina, uterus, pericardiac fluid, trachea, ovary, lung, gallbladder, parotid gland, heart, tonsil, thymus, spleen, pancreas, aqueous humor and cerebrospinal fluid, in that order and not detected in brain. The maximum concentrations in gallbladder, B-bile, pericardiac fluid and cerebrospinal fluid were found at 1-2 hours after administration. In other tissues and body fluids, they were obtained at the end of the infusion period. 3. The area under the tissue concentration curve (AUC) was highest in the urinary bladder followed by the kidney, vagina, liver, uterus, gallbladder, trachea, ovary and lung, in that order. These results suggest that CMNX is useful for various infectious diseases in these tissues. 4. The pharmacokinetic parameter (K11K21) derived from serum and tissue concentrations using the deconvolution method well correlated to maximum tissue concentrations.